All the following are increased in pregnancy except:

(D) Plasma osmolality # Physiological Changes Associated with Pregnancy:> Blood Volume increases progressively from 6-8 weeks gestation (pregnancy) and reaches a maximum at approximately 32-34 weeks with little change thereafter. Most of the added volume of blood is accounted for by an increased capacity of the uterine, breast, renal, striated muscle and cutaneous vascular systems, with no evidence of circulatory overload in the healthy woman.> Rena/ Physiology: Renal plasma flow and glomerular filtration rate begin to increase progressively during the first trimes:er. At term, both are 50-60% higher than in the non-pregnant state.> This parallels the increases in blood volume and cardiac output. The elevations in plasma flow and glomerular filtration result in an elevation in creatinine clearance.> Blood urea and serum creatinine are reduced by 40%.> The increase in glomerular filtration may overwhelm the ability of the renal tubules to reabsorb leading to glucose and protein losses in the urine. Thus, mild glycosuria (1-10 gm/day) and/or proteinuria (to 300 mg/day) can occur in normal pregnancy.> There is also an increase in filtered sodium, but tubular absorption is increased by an increase in aldosterone secretion, via the renin-angiotensin mechanism. There is also a decrease in plasma osmolality.